I don't see why they would say that. Apple has the iPhone on tons of carriers world-wide. They are linked to your itunes account not to the device. Only one I saw saying this was a navigation app that ATT has by the same company that makes a Verizon branded one. The ATT one charges to your cell account while the Verizon one goes via in-app purchases.

Kind of like an email account. Just because you use another computer doesn't mean you can't access it. But it makes sense what Cer0 said. AT&T specific apps that charge to your AT&T account shouldn't work on Verizon. It should be fine, like everyone else said. Verizon is trying to be sneaky

Say what? The Iphone uses either or not both at once......... I have had them since 2008 and never been able to use WIFI and 3g at same time.

That's not entirely true. Push notifications tends to default to using the Cellular connection, even if you're connected to and using wifi. This is even mentioned in documentation for iOS developers: iOS Reference Library

The only times Push is sent via WiFi is when the cellular data connection is broken (no signal, in-call while on a EDGE/CDMA network), or WIFi is enabled while Airplane Mode is turned on.

I jailbreak and have MyWi. I use 3g and distribute wifi to friends at the same time. but it would be pointless for them to both be receiving at the same time. I wonder if the iphone could somehow be made to do that though. that could be the fastest internet connection ever. No?